This beautiful word is not found in OED hyphenated or compound – it is JRRT original for our purposes, and much used by modern fantasy authors.  And my favorite form of the word?  Right here.  The ultimate lullabye.

• 01.076 The dragon-fire, in twisted wire
• 13.009 But certainly it was not a spark of dragon-fire,
• 14.033 Dragon-fire and ruin!
• 15.039 The dragon-fire, from twisted wire